The field of art to which this invention relates is surgical needles and sutures, in particular, surgical needles and sutures for use in cardiac surgery, and cardiac surgical procedures using surgical needles and sutures.
The replacement of diseased or damaged heart valves with artificial heart valves is a relatively common surgical procedures. The replacement of a heart valve is indicated when the native valve becomes sufficiently incompetent such that coronary function is compromised. There are numerous types of conventional artificial heart valves which can be used in such procedures including synthetic mechanical, porcine tissue, cryogenically preserved homografts, and autologous valves from a different position in the patient""s own heart.
In a conventional cardiac heart valve replacement surgical procedure, the patient must typically be placed on cardio-pulmonary by-pass. During cardio-pulmonary by-pass, the flow of blood into and out of the heart and lungs is interrupted, and the blood flow is routed to a conventional blood pump and oxygenation unit. It is known that complications and side-effects are associated with cardio-pulmonary by-pass, and it is generally believed that it is in the best interest of a patient to expedite the cardiac surgical procedure and remove the patent from cardio-pulmonary by-pass as quickly as possible. Complications and side effects associated with cardio-pulmonary surgery typically include the generation of emboli, hemolysis and degradation of the blood""s oxygen carrying capacity, and inflammatory response in the blood. Some or all of these complications are believed by many experts in the field to be caused contact with the components of the cardiopulmonary bypass equipment. It is similarly believed that the severity and incidence of side effects is related to the length of the period of time that the patient is on cardio-pulmonary by-pass.
When performing a typical, conventional heart valve replacement cardiac surgical procedure, the surgeon makes incisions into the thoracic cavity and pericardium, and then into aorta or myocardium in order to have access to the damaged heart valve. The procedure may be an open procedure in which the sternum is sawed and the ribs are spread with a conventional retractor, or a minimally invasive procedure wherein the heart and heart valve are accessed through minimally invasive openings in the thoracic cavity, such as through trocar cannulas or small incisions in the intercostal spaces. The heart may also be accessed through the lumen of an artery. The minimally invasive procedures can be viewed remotely using a camera and monitor, or in some cases directly.
A natural heart value consists of a muscular annulus adjacent to one of the chambers of the heart. A plurality of overlapping leaflets extend radially inward from the annulus into the blood flow path. The leaflets are moveable in a single direction, thereby acting as check valves that inhibit back flow.
Once the surgeon has accessed the damaged or diseased heart valve, the leaflets are surgically removed in a conventional manner, for example using surgical scissors, forceps or graspers. Next, the surgeon measures the annulus in order to select an appropriately sized artificial heart valve. Most conventional artificial heart valves consist of a frame and/or housing containing a flow control element such as a ball, disc, or multiple vanes, etc., configured to allow unidirectional flow. The frame is mounted to a conventional valve sewing ring. The valve sewing ring typically consists of biocompatible synthetic fabric cover over an elastomeric core. The artificial valve is mounted to the surgically prepared annulus of the heart by sewing using a plurality of surgical needle and suture combinations, which have been specifically designed and selected for this application. Typically, the surgical needle and suture combinations are conventional double-armed sutures. That is, a conventional cardiac surgical needle is mounted to each end of a suture, and optionally, a pledget member is mounted to the suture. Each needle is then passed by the surgeon through the annulus and the sewing ring, and the suture mounted to the needle is pulled through the pathway created by the needle. After both ends of the suture have been pulled through, the needles are cut off of the ends of the double-armed sutures to create free ends, and the free ends are then knotted together to tightly affix the sewing ring and valve to the annulus. Typically, a plurality of surgical sutures is required to adequately mount the valve to the annulus, for example, about 12-18 in order to assure a hemostatic seal.
One of the most time consuming aspects of the valve replacement procedure is the suturing of the sewing ring to the annulus. It can be appreciated by those skilled in the art that if, for example, 18 double armed sutures are used in the procedure, then 36 separate needle passes are required.
One critical, primary requirement of the valve replacement surgical procedure is that the junction of the sewing ring and the annulus must be hemostatic, i.e., leakage about the sewing ring is not permitted. Leakage of blood between the sewing ring and the annulus will produce an adverse result. For example, leakage from an inadequately mounted artificial valve can result in regurgitation or backflow of blood which could compromise coronary function. Accordingly, in addition to using a sufficient number of sutures, the sutures must be sufficiently tensioned to prevent leakage. Due to the relatively narrow diameter of the sutures, tensioning can cause a number of complications including suture tearing through tissue or tissue bunching that inhibits correct seating of the valve on the annulus. In order to distribute the force applied on cardiac tissue by the tensioned suture, it is known to mount various types of buttress materials to suture. One type of conventional buttress is known as a pledget. Pledgets are typically made from soft, pliable conventional biocompatible materials. The pledget is mounted to the suture and assists in preventing tissue tear through.
Although the surgical sutures and cardiac surgical procedures of the prior art are adequate for their intended purpose, there is a need in the art for improved cardiac surgical sutures and surgical procedures. In particular, there is a need to provide improved, novel methods of valve replacement surgery wherein the suture mounting time is significantly reduced. Furthermore, improved cardiac needle and suture combinations are needed, along with improved surgical procedures, which will provide for consistent and improved fluid-tight interfaces between a replacement heart valve and an annulus in the heart.
Accordingly, there is a need for novel surgical suture and needle combinations, which can be used, in such novel surgical procedures.
Therefore it is an object of the present invention to provide for novel suture and needle combinations useful in cardiac valve replacement procedures.
It is yet another object of the present invention to provide novel pledgets, which are mounted to the needle and suture combination of the present invention.
It is yet a further object of the present invention to provide a novel method of affixing a replacement heart valve to a valve annulus in the heart using the novel surgical suture and surgical needle combinations of the present invention.
Still yet a further object of the present invention is to provide a kit useful in cardiac valve replacement surgical procedures. The kit consists of a plurality of the novel surgical needle and suture combinations of the present invention.
Accordingly, a surgical suture and surgical needle combination is disclosed. The combination has a surgical needle having a distal end and a proximal suture-mounting end. A distal piercing point extends from the distal end. The combination also has a surgical suture having first and second ends. Each of the suture ends is mounted to the suture mounting end of the surgical needle, thereby forming a loop in the suture. The suture loop has a top adjacent to the ends of the suture, and an opposed bottom. The combination optionally has a pledget member mounted to the suture loop.
Yet another aspect of the present invention is a kit for use in a cardiac valve replacement surgical procedure. The kit consists a plurality of surgical suture and surgical needle combinations. The surgical suture and surgical needle combinations consist of a surgical needle having a distal end and a proximal suture-mounting end. A piercing point extends from the distal end. Each combination also has a surgical suture having first and second ends. Each of the free ends is mounted to the suture mounting end of the surgical needle, thereby forming a loop in the suture. The loop has a top adjacent to the ends of the suture, and an opposed bottom. The combination also has a pledget member mounted to the suture loop. Optionally, half of the combinations have a suture having a first color, and the second half has sutures of a second color. The needle and suture combinations are mounted in a package.
Still yet another aspect of the present invention is a method for surgically mounting a replacement heart valve having a sewing ring onto an annulus of a heart valve, wherein the annulus has an upper surface and a lower surface. The method consists of initially providing a replacement heart valve having a sewing ring. Then the heart valve is implanted in the heart such that the sewing ring is adjacent to and in substantial contact with the upper surface or the lower surface of the annulus of the native valve after the leaflets of said valve have been removed. Next, a plurality of the previously-mentioned surgical suture and surgical needle combinations of the present invention is provided. Each combination has a surgical needle having a distal end with a piercing point, and a proximal suture mounting end. Each combination also has a surgical suture having a first end and a second end. The ends are mounted to the suture mounting end of the needle, thereby forming a suture loop having a top adjacent to the ends of the sutures and an opposed bottom. A pledget member is mounted to the suture loop. Next, the needle is passed through the annulus and sewing ring, and the suture loop is pulled through the annulus and sewing ring until the pledget is substantially in contact with the surface of the annulus. Then, the needle is cut off from the suture loop, thereby providing first and second free suture ends. This step is repeated with the remaining loop suture combinations. Then, the free ends of the sutures are knotted together, thereby securing the valve in place on the annulus. Optionally, one half of the combinations have sutures having a first color, and the other half of the combinations have a suture having a second color. When the surgeon sutures the heart valve to the annulus, combinations of alternating colors are used, and, each free end of the suture of each combination is knotted to a free end of a different colored suture of an adjacent combination, thereby forming a continuous or xe2x80x9cmattressxe2x80x9d stitch around the periphery of the valve.
Still yet another aspect of the present invention is the above-described surgical method wherein the surgical suture and surgical needle combinations do not have pledget members mounted to the suture loops.
These and other aspects and advantages of the present invention will become more apparent from the following description and accompanying drawings.